Similar to strands of DNA, no two person’s fingerprints are exactly alike. It is possible for identical twins to have the same fingerprints, but even environmental factors can alter this fact and ultimately bring us to the same conclusion.

The observation of fingerprints actually began in 14th century Persia when a doctor noticed fingerprints on a few government documents and saw that no two of them were exactly alike. From that time on, various studies made observations but had never really taken fingerprints into consideration for personal identification. The first person to do this was Sir William Herschel when he determined that the handprints of locals on contracts could indeed prove or disprove someone’s identity. Obviously we have come a long way since then, progressing through methods such as Alphonse Bertillion’s, involving the measurement of arms, legs, and other pieces of anatomy, eventually bringing us to the point of using a fingerprint for purposes of forensic science.

Now that we know that these unique characteristics are valuable, fingerprints can supply investigators with a nearly foolproof source to criminalize a person and lead them into conviction or to deem them innocent of breaking the law. By determining how many points are identical in a print located at the scene of a crime versus the print taken from a potential suspect, investigators are enabled with yet another foundation on which to build a case.

There are many different methods that may be used to lift, or take, a fingerprint from the scene of a crime. The oldest and perhaps the most prevalently used technique is using a very fine black powder, sweeping over an object’s surface, and then placing a piece of tape to carefully remove the fine outline of the powder. The human body is constantly excreting fluids by means of the hands and fingers so that power attaches itself to the residue left behind.

Another very common method is to use the same black powder mixed in with tiny magnetic particles, after which the particles can be picked up using a magnetic wand. The prints are then lifted in the same manner as when it was just the powder itself. This assists cleanup and often results in a much clearer depiction of a print. Special sprays and lights may also be used. The method chosen usually has to do with the material being swept, the investigator’s discretion, and the individual situation at hand.

Lindsey Croft is a freelance writer and has been involved in interdisciplinary journalism for the past three years. She currently resides with her family in central Florida.